Galvanically Isolated Amplifiers (GIAs) are used in Switching Mode Power Supplies (SMPSs). Examples of SMPSs include: Direct Current (DC) converters which convert one DC voltage to a different DC voltage, DC power supplies which convert Alternating Current (AC) to DC, inverters which convert DC to AC and bi-directional power converters such as battery inverters which both convert DC to AC and AC to DC. High voltage (HV) circuitry of many SMPSs is normally galvanically isolated from low voltage control logic circuitry. One application of a GIA is to sense and measure currents or voltages in the high voltage circuitry of an SMPS and provide an equivalent analog signal to the low voltage control circuitry.
A GIA could need a wide bandwidth or equivalently a short input-to-output propagation delay to allow for a stable SMPS control loop. Another important GIA parameter could be “dV/dt immunity”, which refers to the GIA's ability to pass an undistorted signal across the SMPS's isolation barrier when there is a significant change in voltage with time (dV/dt) between the high voltage circuitry of the SMPS and its low voltage circuitry.